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摘要翻译：
我们研究了由紧束缚晶格哈密顿量模拟的正常金属环中的电子输运，该环耦合到两个电子库。首先，通过将开口环的每个位置连接到一维引线上，使环中的磁通螺纹均匀退相，扩展了Buttiker的非弹性散射模型，从而实现退相干和耗散。我们发现，在磁通反转下，电导保持对称，随着磁通的变化，Aharonov-Bohm振荡随退相干参数的变化而减小到零，从而表明环中存在退相现象。这种扩展使我们可以类似于四探针测量，找到磁通变化时环位的局部化学势分布和退相干参数。由于量子干涉效应，局域电化学势在环位振荡。预测测得的四点电阻也有波动，甚至可以为负值。然后，我们指出了非对称开环在理想引线和隧道势垒的Fano反共振周围持续电流中闭合环电子本征态的作用。通过确定环的非厄米有效哈密顿量的实特征值，我们证明了即使在无磁通的情况下，非对称环的连续散射态中也存在离散束缚态。我们的方法涉及量子朗之万方程和非平衡格林函数。
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英文标题：
《Electron transport in an open mesoscopic metallic ring》
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作者：
Dibyendu Roy
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最新提交年份：
2007
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分类信息：
一级分类：Physics 物理学
二级分类：Mesoscale and Nanoscale Physics 介观和纳米物理
分类描述：Semiconducting nanostructures: quantum dots, wires, and wells. Single electronics, spintronics, 2d electron gases, quantum Hall effect, nanotubes, graphene, plasmonic nanostructures
半导体纳米结构：量子点、线和阱。单电子学，自旋电子学，二维电子气，量子霍尔效应，纳米管，石墨烯，等离子纳米结构
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一级分类：Physics 物理学
二级分类：Statistical Mechanics 统计力学
分类描述：Phase transitions, thermodynamics, field theory, non-equilibrium phenomena, renormalization group and scaling, integrable models, turbulence
相变，热力学，场论，非平衡现象，重整化群和标度，可积模型，湍流
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英文摘要：
We study electron transport in a normal-metal ring modeled by the tight binding lattice Hamiltonian, coupled to two electron reservoirs. First, Buttiker's model of incorporating inelastic scattering, hence decoherence and dissipation, has been extended by connecting each site of the open ring to one-dimensional leads for uniform dephasing in the ring threaded by magnetic flux. We show with this extension conductance remains symmetric under flux reversal, and Aharonov-Bohm oscillations with changing magnetic flux reduce to zero as a function of the decoherence parameter, thus indicating dephasing in the ring. This extension enables us to find local chemical potential profiles of the ring sites with changing magnetic flux and the decoherence parameter analogously to the four probe measurement. The local electrochemical potential oscillates in the ring sites because of quantum-interference effects. It predicts that measured four-point resistance also fluctuates and even can be negative. Then we point out the role of the closed ring's electronic eigenstates in the persistent current around Fano antiresonances of an asymmetric open ring for both ideal leads and tunnel barriers. Determining the real eigenvalues of the non-Hermitian effective Hamiltonian of the ring, we show that there exist discrete bound states in the continuum of scattering states for the asymmetric ring even in the absence of magnetic flux. Our approach involves quantum Langevin equations and non-equilibrium Green's functions.
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PDF链接：
https://arxiv.org/pdf/707.3245
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